Impulse sender



June 29, 1943.

H. DOHLI;

IMPULSE SENDER Filed Sept. 15, 193'? 2 Sheets-Sheet l INVENTOB I Hl/VP/CH DOHLE Z ATTORN EY June 29, 1943. H. DOHLE IMPULSE SENDER Filed Sept. 15, 19,37

2 Sheets-Sheet 2 INVENTOR obtained by the invention Patented June 29,1943

' hie, Berlin-Alt-Glienicke, Germany;

vested in the Alien Property Custodian Application September 18, 1937. Serial No. 163,606 Germany September 26, 1836 12 Claims. (CL 117-380) This application is an improvement upon the impulse sender disclosed in my prior United States Patent No. 2,251,866, issuedJanuary 24,

1941, which relates to a registering device in which condensers are employed as registering elements and are variously charged in accordance operation to be registered,

with the switching The discharge current from the registering con densers controls the switching operations which are to become eflective at a given time. In the case of the embodiment described in the prior application the switching operations to be performed consist of a numerical selection for setting telephone switches. In order .to be able to determine the 11 ber of impulses to be transmitted by means of the discharge current from the registering condenser a relay is provided which remains energized for a duration determined by the strength of the discharge current and thus determines the number of impulses to be transmitted. e present invention avoids this sensitive relay which is aptto prejudice the eiiiciency oi the'system. The present invention makes a further improvement upon the arrangement according to the prior application in that for determining the charge on the registering condenser which is characteristic of the switching operation to be performed, it is not the charge contained in but the potential across the condenser which is decisive. This means that the value of the capacity of the individual registering condenser can deviate from the nominal value without endangering the eiiicient operation of the register. This advantage is in that for carrying out the switching operation registered by the state of charge of the registering condensers an opposing potential is applied which compensates the potential of the condensers, the required switching operation (the controlling of an impulse sender) being controlled by means of a device for determining the value of the potential at the registering condensers. This opposing potentialaccording to the invention is applied in stages to the condenser and the impulse sender is caused'to transmit one impulse at each stage. As soon as the opposing potential corresponding to the completely discharged state of the register condenser is reached, the device for determining the value of the potential of the registering condenser becomes operative and prevents the impulse sender from transmitting further impulses.

The invention contemplates two embodiments for the step-by-step connection of the opposing potential and these are represented in Figs. and 2.

Fig. 1 represents a circuit in which the ma- .ing potential is applied in stagesby a stap ing switch and Fig. 2 represents a circuit in which the step-by-step application oi the opposing potential is effected by means oi an auxiliary condenser which is discharged in stages by a second condenser.

' Fig. 1 represents a numerical sender for telephone systems having a single set oi keys common to anumber of selecting stages. The keys Ti to Till are connected to individual tappings irom a potential divider which is formed by the resistances Wii to WHO. The numerals 6, II, l6, etc., indicate the voltages which may be obtained at the respective points on the voltage divider. As in the case of the prior pressing one of the keys TI to Til the contact TI is simultaneously closed. Relay x draws up in the following circuit: earth-lu-IT-Iu- X-battery. Assuming that key T! has been depressed, a condenser Ci, C2, etc., is charged in accordance with the potential from the potential divider corresponding to the key T3. Since the potential is divided into 10 stages by the resistances Wii to Willi which may be equal to one another the key T3 is connected to a potential of 18 volts above earth potential; The registering condenser Cl is charged in the following circuit: battery, 51:, T3, 21/, 3a, Si, bank contact 0, Cl, 2n, earth. Relay Y tact Ix, and at contact 2y breaks the charging circuit of the registering condenser. At contact ix, relay Z was energized, and this at contact 32 operates the rotary magnet D8 of the stepping switch S as soon as relay X has been deenergized by contact iy. The rotary margnet DS steps the wipers S1 to SIV one step so that the second registering condenser C2 is set in readiness to register a second digit over wiper SI. The switching operations which have beendescribed are repeated until the condensers CI to C6 are charged in accordance with the keys Ti to Til which have been depressed. As soon as thestepping switch S has reached contact 6, relay U operates over: earth, 8111, U, battery. The energizing of relay Uis the signal that the registered impulses are sion. Through the depression of the key T3 the condenser Ci was charged at a potential of 18 volts. As soon as relay U operates, the condenser Ci is connected over contacts 211 and 3a and contact 6 of wiper S1 in series with the volt battery over wiper M1 on bank contact 0.

application, on de-,

energizes over conto be transmitted in succes- The condenser Cl operates as a battery of :18 volts potential. Accordingly, it applies to the grid of the tube R a potential of 60+ 18:78 volts as against the 60 volts applied to the cathode of the tube, i. e., the grid is given a negative bias of 78-60-18 volts relative to the cathode. This negative bias on the grid blocks the anode current so that relay H cannot energize. Over contact I u,'relay A operates in the following circuit: earth, wiper MII on contact 0, la, 31:, lb, A and battery. The first impulse is transmitted at contact 2a. Contact la switches on relay B, which breaks the energizing circuit for relay A at contact lb. Relays A and B operate together as an automatic interrupter. The resistances connected in multiple with the windings of relays A and B, make these relays somewhat slow to release after theincircuits are opened. Each time relay B energizes, the rotary magnet DM oi the stepping switch M is energized over contact 211 so that the wipers MI and MII are advanced step-by-step on the energization of magnet DM. When wiper MI comes to the next contact the value of the potential on the grid of the tube is altered. The bank contact of wiper MI is connected to the .60 volt tapping. -The bank contact I is connected to the 54 volt tapping and the bank contact 2 to the 48 volt tapping and so on. 'When wiper MI rests on the contact 2 a potential of 48+18=66 volts is applied to the grid, 1. e., the grid still has a bias of --6 volts relative to the cathode. As soon as the wiper has reached the third contact, the potential of 42+18=60 volts is applied to the grid, 1. e., the grid is no longer biased relative to the cathode voltage of 60 volts. Relay H now operates, since the grid no longer blocks the anode current. During the stepping of the stepping switch M to the third contact, relay A was three: times energized so that the depression of the key I has resulted in the transmission of three impulses. As soon as relay H draws up, contact 21: is rendered inoperative by contact 211. Relay K operates over contact 3a and locks up over contactlk, dependent on relay Z. Relays A and B continue to operate as an automatic interrupter and advance the stepping switch M into the rest position. The interruptions at contact 2a however. remain inoperative at this time. By means of contacts lit and 27:: the resistances connected across the windings of relays A and B are disconnected so that these relays now operate more rapidly than before to cause more rapid rotation of the switch Ml As soon as wiper MII has reached the zero position, relay Z operates over its winding ZII in the following circuit: earth, MII, In, In, lw, ZII, battery. During the impulsing by relayA, relay V was energized over contacts 3b and 5a. This relay is slow-to-release and at contact Iv energizes slow relay W. As soon as relay H energized, the circuit for relay V was broken by contact 3h so that relay W released again. The rotary magnet DS was energized over contact 32 by the operation of relay Z, and relay K is restored by means of contact is. Wiper Sl thereby comes to the next contact, so that now the potential across condenser C2 can be transmitted by the step-by-step application of the opposing potential. The switching operations which have been described are repeated.

In order to be able to dial with fewer than six digits a starting key St! is provided. If for example, a two-digit selection is desired the stepping switch S is advanced to the second contact -still obtaining on condenser C1.

by the successive depression of 'two of the keys TI to Till. Since the desired switching operations can now take place the stepping switch must be advanced to contact 6. This is brought- 5 about by depressing the starting key StT whereupon relay X operates in the following circuit: earth, 8111, bank contacts I to 5, I StT, iy, X, battery. Over contact (a: relays Y and Z are energized so that the rotary magnet DS is enl0 ergized over contact 32 and relays X and Y operistered impulse trains to be transmitted. The

key AT is a releasing key by means of which digits already registered can be released.- Reference may be made to the prior application'in which the corresponding switching operations 0' are described.

In the embodiment represented in Fig. 1 the stepping switch M is subjected to hard wear because this stepping switch has to rotate once for every selecting stage. In the embodiment shown in Fig. 2, this stepping switch is replaced by a relay arrangement which is not used to such a great extentyinconnection with two auxiliary condensers. The switching devices are otherwise the same as in the embodiment shown in Fig. 1 so that they need not'be referred to in detail. It will again be assumed that the registering condenser Cl is charged to a potential of 18 volts. The step-by-step application of the opposing potential starts with the operation of 5 relay U as soon as the stepping switch S has reached contact 6. When the stepping switch S is advanced to contact 8, the condenser 01 has been charged to the full potential of 60 volts over contact Zz: earth, Cl, 22', battery. Thus the 40 potential on condenser C1 is connected over contact 21! in series with the 18 volt potential on condenser Cl so that the total potential on the grid of the tube amounts to 60+'18=78 volts. Over contact lu, relay A is energized in the following circuit: earth, la, in, lb, A, battery. Re-

lay B is energized by contact I a. Over contacts 3b and 2b the condenser C8 is charged at the full potential of volts. C8 is considerably less than that of condenser The condenser C8 is therefore charged in the opposite sense when the condensers C1 and C8 are connected in series to earth over contact 2b and 3b. When relay B energizes the charge on condenser Cl is accordingly reduced by an 55 amount corresponding to the charge on condenser C8. The charge on condenser Cl is then diminished a further amount which corresponds to the charge now imparted by condenser C1 to condenser C8 in accordance with the potential The dimensions of the condensers C1 and C8 are so chosen that the reduction of the potential on condenser C1 by the step-by-step discharge over condenser C8 takes place in convenient stages as regards poten- 05 tial. In the example given the potential of 18 volts on the registering condenser Cl is to be compensated, by connecting the condenser C8 to the condenser 01 three times. As soon as condenser C'l possesses the opposing potential corresponding to that of the registering condenser,

relay H pulls up so that relay Z energizes over contact In and the impulse sending relay A is brought to rest. Relay Z over contact 32 operates the rotary magnet DS and thereby causes wiper SI to be advanced to the next contact. The

The capacity of condenser said third condenser in a Whatisclaiinedis: 1. In an impulse sender for registering a digit as a quantity orcharge on a condenser and subsequently retransmitting the digit as one or more r -in series to remove a portion of the charge from last-named means being repeatedly operableto impulseaa plurality of sources or potential, each source diiiering from the other sources in the value of its potential, means !or successively connecting said sourcesor potential in series with said condenser during the transmission of the impulses, and means operated -to terminate the transmission of the impulses when the combined voltages of said condenser and that one of said sources connected inseries therewith equals a predetermined value.

2. In an impulse sender in which a digit is registered as a quantity of charge on a condenser, means for connecting a source 01 voltage in series with the charged condenser and tor progressively reducing the voltage of said source, means for producing and transmitting an impulse .each time said voltage source is reduced in value, and means controlled conjointly by the condenser and said first means to terminate the transmission of said impulses when the voltage of said charged condenser plus the voltage of said source reaches a predetermined value.

3. In combination,- a condenser, means for charging said condenser to a predetermined potential, a source of potential, means for connecting said potential source in series with said charged condenser, means for reducing the potential of said, source in substantially uniform steps, and means operated responsive to the sum oi the potential of said charged condenser and said source of potential reaching a predeter mined value.

4. In combination, a first condenser, means for charging said first condenser to any one of a plurality of predetermined potentials, a second condenser, means for charging said second condenser, a third condenser, means for intermittently connecting said third condenser with said second condenser to reduce the charge on said second condenser in substantially uniform steps, means for connecting said second condenser in series with said first condenser, and means controlled by said first and second condensers operated when the sum of their potentials reaches a predetermined value.

5. In combination with a grid controlled space discharge device; means for controlling the potential of the grid, comprising;,a first condenser;

means for charging said first condenser to a predetermined value; a second condenser; means for charging said second condenser; means for connecting said condensers in series to said grid,

thereby to establish on said grid a potential dependent upon the algebraic sum of the charges on said two condensers; a third condenser; and means for altering the potential on said grid by charging said third condenser in a direction opposite to the charge contained in the second condenser, connecting said second and third condensers in series to partly discharge said second condenser, and disconnecting said third condenser from said second condenser. v v

6. In combination; a first condenser; means for charging said first condenser to' any one of a plurality of different values; a second condenser; means for charging said second condenser; a third condenser; means for charging direction opposite to said second condenser, and (or disconnecting said third condenser from said second condenser, said reduce the charge on said second condenser in substantially uniiorm steps; and means under the Joint control of said first condenser and said second condenser operated responsive to the charge on said second condenser reaching a value which bears a predetermined relationship to the value of said charge on said first condenser.

7. In combination; a first condenser; means for charging said first condenser to a predetermined value; a second condenser; means (or charging said second condenser; means for connecting said condensers in series; a third condenser; means for charging said third condenser in a direction opposite to the charge contained in the second condenser, for connecting said second and third condensers in series to remove a portion or the charge from said second condenser, and for disconnecting said third condenser from said second condenser, said last named means being repeatedly operable to reduce the sum of the potentials of said first and second condensers in substantially uniform steps, and means controlled in accordance with said sum of potentials and operated when the sum reaches a predetermined value.

8. In combination, a plurality of sources of potential varying in value from each other in substantially uniform steps, a condenser, means for charging said condenser from one of said sources, a potential responsive device, means for connecting said charged condenser to said potentialresponsive device and for connecting said condensersuccessively to each of said sources, said device operating when the sum of the potentials thus obtained reaches a predetermined value.

9. In an impulse sender for registering a digit as quantity of charge on a condenser and subsequently retransmitting the digit as one or more impulses; means for successively connecting a plurality of different potentials of diminishing values in series with said condenser to successively reduce the effective total potential in substantially uniform steps, the number of steps required to reduce said eflective total potential to a predetermined value being thus a measure of the charge on the condenser and hence characteristic of the digit registered. I

10. In combination, a condenser, means for charging said condenser to any of aplurality of diiIerent potentials, a space discharge device having a grid, means for completing a biassing circuit to said grid, said circuit including said charged condenser and, in series with said condenser, an auxiliary potential, said condenserand said auxiliary potential so poled in said circuit that each tends to bias said grid negatively. whereby said condenser and said auxiliary potential together raise the total negative potential of oi said grid reaching the value at which said device discharges.

11-. In combination, a source of direct current, a voltage divider shunting said source, a condenser, means for connecting said condenser denser at each of said times in accordance with the voltage drop in the portion across which said condenser is connected, means operated each time said condenser has been thus charged for thereafter connecting said condenser successively to diflerent portions of said voltage divider without altering the original charge on said condenser, and means for testing the effective total potential of said charged condenser and each said portion of said voltage divider as the condenser is connected to that portion.

12. In combination, a condenser, a source of direct current voltage, means for connecting said condenser to said source to charge the condenser, means operated after said condenser has been charged for connecting the charged condenser and said source in series so that the effective total potential of said condenser and said source together is greater than the potential of either said condenser or said source alone, meansfor then gradually reducing the voltage of said source without altering the charge on said condenser, and a device operated responsive to said efiective total potential of said condenser and reaching a predetermined value.

1 HINRICH said source 

